Today is defined as Pi day, it is also Albert Einstein's birthday. Besides, today is Japaness lover's "white day".

According to Wiki, "In the 1980s the Japanese National Confectionery Industry Association launched a successful campaign to make March 14 a "reply day", where men are expected to return the favour to those who gave them chocolates on Valentine's Day, calling it White Day for the color of the chocolates being offered."

These are my Eprint papers. Some have already been published as Journal papers, some have not.

I will discuss some of them here someday.

You can link to http://arxiv.org/ and search my name Pi-Gang Luan in Physics [arxive: All], and these papers would be shown to you. There is an exception, my YBE paper ([Colored solutions of Yang-Baxter equation from representations of U_{q}gl(2)] ). In that case you should type [Pi-Gang Luan] instead of Pi-Gang Luan to find the paper.

From now on I want to share with you my research experiences and personal opinion on time dependent quantum system, photonic/sonic crystals, and metamaterials. I would also like to write some articles on science teaching stuff.

I come from Taiwan. Usually I speak chinese, and have no many oppernituties to practice my English, so I wish someone can help me to improve my English. Thanks !